Comparative morphology of the ossicles of ophiuroids using micro-computed tomography: Which ossicles are morphologically conservative in evolution?

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07549
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biodiversity/Systematics
• Research Institution: National Museum of Nature and Science, Tokyo
• Principal Investigator: Fujita Toshihiko 独立行政法人国立科学博物館, 動物研究部, グループ長 (70222263)
• Co-Investigator(Kenkyū-buntansha): 岡西 政典 東京大学, 大学院理学系研究科(理学部), 特任助教 (70639278)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 系統 / 分類 / 進化 / クモヒトデ類 / 形質 / マイクロCT / 非破壊 / 保存性

Outline of Final Research Achievements

Ophiuroids (Echinodermata) has a skeleton of many kinds of numerous ossicles supporting their body. Compared to soft tissue, the form and arrangement of hard ossicles have been intensely used for the conventional ophiuroid classification. The detailed morphology of many ossicles including internal ones which have been scarcely observed was examined by using micro CT, and some ossicles were newly proved available as taxonomical features at each taxonomic rank from species to higher taxa. Based on the molecular phylogeny, these ossicles will be re-evaluated as taxonomic characteristics in terms of how conservative they are in the lineages of ophiuroids.

Free Research Field

動物系統分類学

Academic Significance and Societal Importance of the Research Achievements

生物は進化によって，様々な形態を生み出してきた．形態がそれぞれの系統でどのように変化したのかを追うことは，進化を理解する上での重要な課題である．様々な系統において，どのような形質でも等しく変化するわけではなく，発生における条件や機能など多くの要素に関連して，形質の変化のしやすさが異なっていると想定される．系統に基づく分類体系と分類形質を対照させた分析から，各形質の進化における保存性の差異を明らかにすることで，生物進化の理解を進めることができる．